Hardware logic arranged to normalise (or renormalise) an n-bit input number is described in which at least a proportion of a left shifting operation is performed in parallel with a leading zero count operation. In various embodiments the left shifting and the leading zero count are performed independently. In various other embodiments, a subset of the bits output by a leading zero counter are input to a left shifter and the output from the left shifter is input to a renormalisation block which completes the remainder of the left shifting operation independently of any further input from the leading zero counter.

An instruction generates a value for use in processing within a computing environment. The instruction obtains a sign control associated with the instruction, and shifts an input value of the instruction in a specified direction by a selected amount to provide a result. The result is placed in a first designated location in a register, and the sign, which is based on the sign control, is placed in a second designated location of the register. The result and the sign provide a signed value to be used in processing within the computing environment.

A layout pattern of a two-port ternary content addressable memory (TCAM) includes a first storage unit, a second storage unit, a first comparison circuit and a second comparison circuit. The first comparison circuit and the second comparison circuit are positioned in a first side area of a side and a second side area of another side of the layout pattern, respectively. The first storage unit and the second storage unit are positioned in a first middle area and a second middle area between the first side area and the second side area, respectively. The first storage unit is connected to the first comparison circuit through a first gate structure and connected to the second comparison circuit through a second gate structure. The second storage unit is connected to the first comparison circuit through a third gate structure and connected to the second comparison circuit through a fourth gate structure.

Approximation circuitry utilizes bitwise operations on operands to provide approximate results of operations on the operands. A significant digit detector utilizes bitwise operations on the received operands to identify or detect approximate most significant bits in the operands, and then utilizes these identified most significant bits to generate approximate values for each of the operands. Intermediate registers receive and store the approximate values from the significant digit detector. A combinatorial network, such as a lookup table (LUT), thereafter utilizes the approximate values stored in the intermediate registers to generate an approximate result. The approximate result has a value that is an approximate value of a given operation, such as multiplication or division, on the operands provided to the significant digit detector.

An in-memory vector addition method for a dynamic random access memory (DRAM) is disclosed which includes consecutively transposing two numbers across a plurality of rows of the DRAM, each number transposed across a fixed number of rows associated with a corresponding number of bits, assigning a scratch-pad including two consecutive bits for each bit of each number being added, two consecutive bits for carry-in (C.sub.in), and two consecutive bits for carry-out-bar (C.sub.out), assigning a plurality of bits in a transposed orientation to hold results as a sum of the two numbers, for each bit position of the two numbers: computing the associated sum of the bit position; and placing the computed sum in the associated bit of the sum.

An in-memory vector addition method for a dynamic random access memory (DRAM) is disclosed which includes consecutively transposing two numbers across a plurality of rows of the DRAM, each number transposed across a fixed number of rows associated with a corresponding number of bits, assigning a scratch-pad including two consecutive bits for each bit of each number being added, two consecutive bits for carry-in (C.sub.in), and two consecutive bits for carry-out-bar (C.sub.out), assigning a plurality of bits in a transposed orientation to hold results as a sum of the two numbers, for each bit position of the two numbers: computing the associated sum of the bit position; and placing the computed sum in the associated bit of the sum.

Accumulator hardware logic includes first and second addition logic units and a store. The first addition logic unit comprises a first input, a second input and an output, each of the first and second inputs arranged to receive an input value in each clock cycle. The second addition logic unit comprises a first input that is connected directly to the output of the first addition logic unit. It also comprises a second input and an output. The store is arranged to store a result output by the second addition logic unit. The accumulator hardware logic further comprises shifting hardware and/or negation hardware positioned in a feedback path between the store and the second input of the second addition logic unit. The shifting hardware is configured to perform a shift by a fixed number of bit positions in a fixed direction.

Methods and leading zero anticipators for estimating the number of leading zeros in a result of a fixed point arithmetic operation which is accurate to within one bit for any signed fixed point numbers. The leading zero anticipator includes an input encoding circuit which generates an encoded input string from the fixed point numbers; a window-based surrogate string generation circuit which generates a surrogate string whose leading one is an estimate of the leading one in the result of the arithmetic operation by examining consecutive windows of the encoded input string and setting corresponding bits of the surrogate string based on the examinations; and a counter circuit configured to estimate the number of leading zeros in the result of the arithmetic operation based on the leading one in the surrogate string.

Methods and leading zero anticipators for estimating the number of leading zeros in a result of a fixed point arithmetic operation which is accurate to within one bit for any signed fixed point numbers. The leading zero anticipator includes an input encoding circuit which generates an encoded input string from the fixed point numbers; a window-based surrogate string generation circuit which generates a surrogate string whose leading one is an estimate of the leading one in the result of the arithmetic operation by examining consecutive windows of the encoded input string and setting corresponding bits of the surrogate string based on the examinations; and a counter circuit configured to estimate the number of leading zeros in the result of the arithmetic operation based on the leading one in the surrogate string.

Circuits and associated methods for processing two floating-point numbers (A, B) to generate a sum (A+B) of the two numbers and a difference (A-B) of the two numbers include calculating (806) a sum (|A|+|B|) of the absolute values of the two floating-point numbers, using a same-sign floating-point adder (1020), to produce a first result. The method further comprises calculating (808) a difference (|A||B|) of the absolute values to produce a second result. The sum (A+B) and the difference (A-B) are generated (810, 812) based on the first result (|A|+|B|), the second result (|A||B|), and the sign of each floating-point number.